This invention relates generally to microsurgical and ophthalmic systems and, particularly, to circuitry for operating and controlling a variety of handpieces and probe adapted to function as, for example, intraocular scissors or forceps, which handpieces are electrically isolated for circuitry activated by foot pedal controls.
Present day ophthalmic microsurgical systems provide one or more surgical instruments connected to a control console. The instruments are often electrically or pneumatically operated and the control console provides electrical or fluid pressure control signals for operating the instruments. The control console usually includes several different types of human actuable controllers for generating the control signals supplied to the surgical instruments. Often, the surgeon uses a foot pedal controller to remotely control the surgical instruments.
The use of intraocular surgical handpiece instruments functioning as scissors or forceps is well known in the art. While manually operated ophthalmic scissors and forceps are still in use worldwide, they suffer from the disadvantage of being subject to human limitations for speed and accuracy. Therefore, the use of surgical scissors and forceps having electric drive means, whether it be a solenoid, stepper motor or direct current motor, has become increasingly widespread.
Prior art circuits for electrically controlled intraocular surgical handpieces that are removable from common controlling hardware have included an apparatus for sensing the presence of the handpiece, but the handpiece and the sensing apparatus have been connected to the electrical power source, thereby operating in a grounded patient configuration. Such prior art circuit configurations leave a patient vulnerable to injury from the power source of the ophthalmic surgical hardware in the event that the hardware is electrically defective. Such configurations also leave a patient vulnerable to injury form the power sources of any electrically defective equipment that may be being used in conjunction with the ophthalmic surgical hardware.